1. Technical Field
The present invention relates to an electro-optical device in which an electrostatic protection element is formed in a substrate, an electronic apparatus including the electro-optical device, and a semiconductor device in which an electrostatic protection element is formed in a substrate.
2. Related Art
In an element substrate or a semiconductor device which is used for an electro-optical device such as a liquid crystal device, an electrostatic protection element which is configured by a diode-connected MOS type transistor is provided between a signal line and a constant potential line (refer to JP-A-2004-303774 and JP-A-2011-222971). If a large current flows through a drain region of the MOS type transistor when the electrostatic protection element discharges static electricity, there is a possibility that the electrostatic protection element may be damaged by the heat generated at the time. Thus, JP-A-2004-303774 proposes that a contact with a drain side is appropriately provided and a distance from a gate terminal is lengthened. In addition, JP-A-2011-222971 proposes that a trench is provided in the drain region, and a distance from the gate terminal is substantially lengthened.
However, in a case in which an insulating film such as a silicon oxide is provided in a portion of a substrate and an electrostatic protection element is provided on the insulating film, a heat dissipation property from the electrostatic protection element to the periphery is decreased, and thus there is a problem that damage caused by heat generation in the drain region cannot be prevented by configurations described in JP-A-2004-303774 and JP-A-2011-222971.